Hi kienan, There is no guarantee that they have a BMS in them, not all lithium do.
A simple test is to take them up carefully to a higher voltage, but not too high, to see if they turn off. As to info about them I’d want to know. Chemistry ( would be good to know if they are capable of catching on fire) Cycle life Just sucks seeing people getting screwed. Jay > On Mar 4, 2019, at 5:23 AM, Kienan Maxfield <[email protected]> wrote: > > Hello all, > > I just got back from looking at an off-grid system that is only about 4 > months old or so, and it has several problems. I have specialized in off-grid > for 8 years, so most of the problems will be easy for me, but there's just > one thing that is a bit perplexing and I'm hoping someone might have some > advice. > > The system was "designed" by some retailer in Texas (I don't know who) and > the home-owner found some local installer to put it together for him (they > already charged a ridiculous price and they won't come back). The battery is > a big bank of DKD LiFePO4 batteries, each one says 100 Ah @ 12.8V. They are > in series sets of 4 for 48V. I think there were 5 strings (500 ah total). > There are no com wires from battery to battery or anything like that (nor did > I find anywhere for com ports). I have not yet been successful in finding any > information about these batteries online. I'm not that familiar with this > type of battery and I'm hoping that some of you might have some info/insight > on a couple of questions about this situation. Here's a picture of one of the > batteries, > > <IMG_4362.jpg> > > The biggest question is if this configuration is okay. I'm not familiar with > this type of batteries, but I saw at least one brand that said not to put > their batteries in series. They said that (at least with their brand) if you > needed a 48V battery, you couldn't use (4) 12V batteries. > Does anybody have any thoughts (positive or negative) or experiences with > these batteries? > Does anybody have any technical information (like a voltage/SOC curve or > anything else) for these batteries? > I will be fixing the other things in his system, but when he asks what I > think about his battery bank, I don't know what to tell him at this point. He > also has no idea how to tell how full his batteries are, and since it doesn't > seem like his batteries have any kind of readout or anything, I'm not sure > what to tell him on that either. If I could find a Voltage/SOC curve or a > voltage/SOC conversion table, that would help on that front. > > Thank-you, > Kienan > > > Maxfield Solar > [email protected] > (801) 477-0-SUN (477-0786) > (801) 631-5584 (Cell) (preferable contact number) > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/[email protected]/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org >
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